ruby on rails - Better way to make nested resources? -

in routes.rb have following code create nested paths students , subjects under student_groups:

resources :student_groups   resources :students, :subjects end 

i want nest goals under subjects without generating new routes subjects along nested routes goals. i've done via following (plus appropriate stub action in subject_controller):

resources :subjects, :only => :stub   resources :goals end  

this works fine - have functionality of goals being nested under subjects without routes generated if didn't use stub.

edit: question this: there better/less hack-y way in rails?